English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the influence of diagonal disorder (random site energy) of localpair (LP) site energies on the superconducting properties of a system ofcoexisting local pairs and itinerant electrons described by the (hard-core)boson-fermion model. Our analysis shows that the properties of such a modelwith s-wave pairing can be very strongly affected by the diagonal disorder inLP subsystem (the randomness of the LP site energies). This is in contrast withthe conventional s-wave BCS superconductors, which according to the Anderson'stheorem are rather insensitive to the diagonal disorder (i.e. to nonmagneticimpurities). It has been found that the disorder effects depend in a crucialway on the total particle concentration n and the LP level position DELTA_o anddepending on the parameters the system can exhibit various types ofsuperconducting behaviour, including the LP-like, intermediate (MIXED)and the'BCS'-like. In the extended range of {n,DELTA_o} the superconducting orderingis suppressed by the randomness of the LP site energies and the increasingdisorder induces a changeover from the MIXEDlike behaviour to the BCS-like one,connected with abrupt reduction of T_c and energy gap to zero. However, therealso exist a definite range of {n,DELTA_o} in which the increasing disorder hasa quite different effect: namely it can substantially enhance T_c or even leadto the phenomenon which can be called disorder induced superconductivity.Another interesting effect is a possibility of a disorder induced bound pairformation of itinerant electrons, connected with the change-over to the LP-likeregime.

Effects of Disorder on Superconductivity of Systems with Coexisting Itinerant Electrons and Local Pairs